Photographing Comets From Your Backyard

Comets are rare and beautiful phenomena. It is not often that they pass by the Earth and are visible enough to be seen by virtually everyone.

The appearance of Comet NEOWISE (the astronomer catalog number is C/2020 F3) has sent droves of us into our backyards in the early evening hours to see the spectacle. If your skies are dark enough, it is visible to the naked eye, and even if you live under city lights it can usually be found with a pair of binoculars.

The sight of such cosmic wonders often inspires a deep desire to capture the view as a picture, for later contemplation. If you have a modern DSLR (digital SLR), this Instructable will show you how I capture pictures of the comet. I took the picture above from my backyard in suburban Chicago. You can do it too!

NEOWISE will certainly not be the last comet to grace our skies, so file these instructions away, and keep them handy when the next one swings by.

Even if you don't have a DSLR, you can still try and capture the comet in an image. All you really need is the ability to make sensitive pictures in near darkness ("night mode"), or exposures between 1 and 5 seconds long.

The image above was captured by my daughter using an iPhone 11! The image is grainy, but the comet is definitely there! If you browse the web, you'll find many examples of phone pictures taken of the comet, and can get some inspiration.

To follow these isntructions, you need:

• Digital SLR (I have a Canon T3i)
• Any lens (I've shot the comet with both of my lenses!)
• Binoculars (to enjoy looking at the comet with your eyeballs)
• Tripod

If you've never futzed around with your DSLR before, it is best to try it indoors before you go out, just to know where all the buttons are. There aren't many you need to know to follow this Instructable, but it will be easier in your dining room, rather than in the dark in your backyard!

The tripod is simply to hold the camera still during the multi-second exposure; the camera does not need to track the comet to get a good picture of it! If you have a shutter release cable, you can use it to remotely trigger the shutter, but I haven't had any problems just pushing the shutter button if the camera is mounted on my tripod.

At the moment, Comet NEOWISE is visible to people in the northern hemisphere, about an hour after sunset, in the northwest skies. It should be visible for at least the next 7 to 10 days (until early August 2020).

The chart above shows the location of NEOWISE for the next couple of weeks as it moves slowly across the sky. The Big Dipper is the most prominent group of stars near the comet, and it has been marked here in orange. It is usually visible, even if you live in a fairly bright city.

When you first go out, face to the Northwest, and see if you can identify the Big Dipper. Sweep your eyes back and forth in the area below the Big Dipper -- more than likely your eye will be able to see the comet, though you may only be able to see the bright head of the comet (called the "coma") and you'll think it is a star.

This is where you binoculars come in. My binoculars are shown above -- they're the ones I keep on my coffee table and use to watch squirrels and birds. Using your binoculars, look for a bright star (any bright star) and make sure the star looks focused.

Now sweep the binoculars back and forth under the Big Dipper slowly, and you should be able to find the comet after a few passes. If you can't find it, wait maybe 10 or 15 minutes, until it gets a bit darker then try again.

Once you find it in binoculars, you may know enough what you are seeing to spot it with your unaided eye.

There are no perfect settings to get the perfect comet picture.

ISO SETTINGS. I typically shoot at ISO 800, or ISO 1600. ISO 800 pictures are darker, but ISO 1600 pictures are a little bit grainier.

EXPOSURE. I use the "Manual" (M) mode, so I can control all the settings, including the shutter speed. I have experimented with exposures between 1 second and 6 seconds. There is enough light pollution around me that 6 second exposures are pretty washed out, so I usually settle in around 4 second exposures.

These settings will get you started, and you can look at each picture you take on your viewscreen and see if you can see the comet. If not, increase your exposure or increase your ISO.

Don't feel rushed -- each night, the comet will be visible for an hour or more, so take some time to experiment with the settings to see what gives you a good image. We'll talk a bit about post processing in Step 8.

Focusing your camera for sky pictures is the most involved part of this exercise. Almost nothing you can photograph in the sky is bright enough for the auto-focus to work on (the notable exception is the Moon), so turn the autofocus off.

The magical trick to focusing for night sky pictures is to use "Live View."

On most DSLRs you can look through the viewfinder, holding the camera up to your eye like a traditional photographer would. Live View blocks the viewfinder and instead sends the image to the viewscreen on your camera.

There should be a button to switch between the ViewFinder and the LiveView -- on my camera, it is right next to the view finder, as shown in the 1st picture above. When you switch to LiveView, the screen displays what the camera is seeing, as shown in the 2nd picture above.

The last thing you need to know about LiveView is how to magnify. On my camera, the selection button on the back of the camera body, just below the shutter button. It switches LiveView between 1x, 4x, and 10x magnification. We are going to use the 10x mode for focusing.

To get focused using Live View, look for a bright star, the brightest one you can see. Right now there is one high in the sky called Vega, slightly to the east of overhead.

Start with your focus turned all the way to infinity -- it won't be perfect for astro pictures, but it will be close enough to get us ready to focus.

• Switch your camera to LiveView
• Point your camera at this bright star, and get it in the center box on your screen (1st image)
• Magnify the LiveView to 10x (2nd image); the star will be unfocused
• Watching the LiveView, make small manual adjustments to the focus until the star is as much like a point as you can get it (3rd image)

At this point you are focused. Do not change the focus!

Tip your camera down, and turn it toward the region of the sky where the comet is. You're ready to go!

(Author's Note: the hardest thing about making this Instructable was photographing the LiveView screen in the dark!)

Here are two pictures directly off the camera, without any processing.

1st Image: ISO 800, 3 second exposure

2nd Image: ISO 1600, 5 second exposure

These pictures were taken on two different nights, from slightly different locations in my backyard. I like the trees in the foreground, since they provide a little bit of composition, and help give the image a sense of scale.

These images certainly show the comet, but a little post processing in a photo-editing program can improve the visibility.

Programs like Photoshop can give you very precise and varied control over virtually every aspect of a digital image, but knowing what to do is mind-boggling if you are a beginner.

Fortunately, most comet images directly off your camera can benefit from simple adjustments of the levels. The images above are the same two images from the last step, but have been adjusted using the simple "Adjust Level" features in the Macintosh "Preview" Application. "Paint" or Image Viewing applications on Windows should have similar functionality (any Windows users reading this, let me know in the comments what to tell people!).

Under the Tools Menu, select "Adjust Color..." and the control window will pop up.

1st Image: In this image, I simply tapped "Auto Levels" and you can see the software blows the image out; I think it is trying to make the trees look good.

2nd Image: After tapping "Auto Levels", grab the three sliders over the "Auto Levels" button, and slide them back and forth. Generally I adjust the two on the right, and produce a good looking comet image!

3rd Image: Tapping the "Auto Levels" blows out the image

4th Image: Moving the sliders rebalances the image into a nice comet picture.

That is everything I know about taking comet pictures! Try and take a few of your own, and send them to your family and post them to social media!

If you found this Instructable helpful, post your comet pictures in the comments!

I leave you with a few of my best Comet NEOWISE pictures -- check out the fireflies!

Happy Comet Hunting!